Elastic fluid turbine arrangement



Oct. 19, 1943. H. KRAFT ELASTIC FLUID TURBINE ARRANGEMENT Filed Nov. 16,1940 Inventor:

v H ahs K'PaFt, by WW c.

His Attorn ey.

Patented Oct. 19,1943

UNITED ,TS'l'ATES- PATENT OFFICE anasrro FLUID- rename ARRANGEMENT HansKraft, Schenectady, N. Y., asslgnor to Gencral'Electrlc Company, acorporation of New v York Application Name; 16, 1940, Serial No. 365,905

Claims. (or. 253-76) er of fluid in the stationary nozzle passages iseifectively removed. a

This is accomplished in accordance with my invention by the provision ofan elastic fluid turbine having a row or rows of stationary nozto-ashaft 21. A row of radial buckets 28 is suitably secured to the rim ofthe disk 26 and a shroud band 29 is fastened to the outer ends of thebuckets. Each diaphragm has an inner member or disk 30 sealed to theshaft 21 by a packing 3| and a row of partitions or blades 32 securedbetween the rim of the disk and an outer zles for conducting elasticfluid to rows of buck- 'ets on a bucket wheel or wheels, which bucketshave a radial h'eight smaller than the radial height of thecorresponding nozzle passages. Scoops are provided adjacent the innerand outer ends of the buckets for receiving fluid from the boundarylayer and conducting it to a channel. This fluid in accordance with myinvention is utilized for preheating condensate discharged from theturbine condenser.

Fora better understanding of what I believe to be novel and myinvention, attention is directed to the following description and theclaims appended thereto in connection with the accompanying drawing.

In the drawing Fig. 1 illustrates an elastic fluid turbine arrangementin accordance with my invention; Fig. 2 is an enlarged sectional view ofa part of Fig. 1; and Fig. 3 is a sectional view along line 3-3 of Fig.2.

The arrangement comprises an elastic fluid turbine In with a shell H andan exhaust conduit l2 connected to a condenser l3. Condensate dischargedfrom the condenser I 3 is forced by means oi'a condensate pump l4 to aflrst preh'eater I5 having a heating coil l6 and being connected todischarge preheated condensate into a second preheater I! with a heatingcoil I 8. The preheater i! has a discharge conduit I!) for connection toan elastic fluidgenerator or boiler, not shown. The heating coils'lfi'and I8 of the preheaters l5 and I! are connected to supply conduits and2| respectively for receiving heating fluid from the turbine.

The turbine as shown in Fig. 2 has bucket wheels 22, 23 and diaphragms24 and 25 for conducting elastic fiuid to the wheels 22, 23respectively. Each bucket wheel has a disk 26 secured ring 33 held onthe casing ll. 1

During operation, elastic fluid is directed by the nozzle passagesformed between the blades 32 of the high pressure diaphragm 24 towardsthe bucke'ts28 of the bucket wheel 22. The, fluid I discharged from thebucket wheel 22 is conducted through the nozzle passages formed by thesecond or low pressure diaphragm 25 to the bucket wheel 23. I

The fluid flowing through the nozzle passages has maximum velocity inthe central portion of these passages. The velocity decreases towardsthe outer portion and becomes a minimum at the walls formed by theblades, the disk 30, and the ring 33. Thus, during operation a boundarylayer of relatively slowly flowing fluid is formed in each passage. Thisboundary layer of slowly flowing fluid does little work when conductedinto' the passages formed between the buckets of a bucket wheel.Therefore, in accordance with my invention, means are providedpreventing at least part of the boundary layer-oi fluid in thestationary diaphragms from entering the rotating bucket wheels. To thisend the buckets 28 of the bucket wheels have aradial length or heightsmaller than the radial length or height of the blades or partitions 32of the corresponding diaphragms. The. outer and inner ends of the thinoutlet edges of-the partitions 32 are cut away to form a shortenedintermediate outlet edge 3 closely spaced with the buckets of thesucceeding wheel.

The ends of the partitions extend radially beyond the ends of the.corresponding buckets. From another viewpoint, the disk of the bucketwheel 22 has a larger diameter than the disk 30 32. Similarly the casingH is provided with annular projections 36 closely spaced with thecutaway, outer, thin outlet edges of the blades 32 and forming scoopsfor receiving the boundary 7 layers formed in the outer portions of thenozzle passages. The fluidof the outer boundary layers is conductedthrough a passage 31 formed between the outer ring 33 of the diaphragmand the casing ll into a channel or channels 38 which discharges thefluid into a chamber 39 formed by the casing II.

The inner boundary layer in the nozzle passages is received by thescoops 35 and conducted into a space 40 formed between adjacentdiaphragms and bucket wheels, whence the fluid is conducted to theaforementioned chamber 33 of the casing II. To this end the thick inletportions of at least some of the partitions or blades 32 are providedwith radial bores 4| which at their inner ends communicate throughchannels 42 with the space 40 and at their outer ends communicatethrough channels 43 with the channels 38.

During operation fluid flowing through the central portions of thenozzle passages is conducted to the bucket wheels whereas the innerboundary layer is conducted through the space 40, the channels 42, thebores 4| and the channels 43 and 38 to the chamber 39. The space 40 alsoreceives leakage fluid flowing along the shaft. The fluid of the outerboundary layer is conducted through the passage 43 and the channel 38 tothe chamber 39.

In the present arrangement the chamber 39 receives the fluid of theboundary layers from the two diaphragms 24 and 25. The chamber 39 isconnected to discharge fluid into the aforementioned supply conduit 2|for preheating the condensate in the second preheater H. A similarchamber 44 (Fig. 1) is formed to receive fluid from boundary layers 01lower turbine stages and discharge such fluid into the supply conduit 20of the first preheater I 5.

Having described the method of operation of my invention, together withthe apparatus which I- now consider to represent the best embodimentthereof, I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. Elastic fluid turbine comprising a casing, a

diaphragm supported on the casing and forming a row of nozzle passagesand a bucket wheel having a row of buckets associated with the nozzlesnozzle passages from entering the bucket wheel to separate the boundarylayers of fluid from the remaining fluid.

2. Elastic fluid turbine comprising a casing, a diaphragm supported onthe casing and forming a row of nozzles, a bucket wheel having a row ofbuckets associated with the nozzles and being of a radial height shorterthan the radial height of the nozzle passages, the bucket wheel diameterat the inner ends of the buckets being larger than the diaphragmdiameter at the inner ends of the nozzles, and means including a scoopformed on the bucket wheel adjacent the roots of the buckets forreceiving the inner boundary layer from the nozzle passages, and channelmeans for removing said layer from the turbine.

3. Elastic fluid turbine comprising a casing forming a fluid chamber, adiaphragm having a disk, a plurality of radial partitions with innerends secured to the disk and an outer ring supported on the casing andsecured to the outer ends ofthepartitions, a bucket wheel having a rowof buckets for receiving fluid from the diaphragm, the radial height ofthe buckets being smaller than the radial height of the partitions, andmeans forming channels for conducting fluid from the inner and outerboundary layers formed in the nozzle passages to said chamber toseparate the fluid of the boundary layer from the remaining fluid and toremove the fluid of the boundary layers from the turbine, said meansincluding the disk and the ring and radial bores through at least someof the partitions.

4. Elastic fluid turbine comprising a casing forming a fluid chamber, adiaphragm having a disk, a plurality of radial partitions with innerends secured to the disk and an outer ring supported on the casing andsecured to the outer ends of the partitions, a rotor comprising a shaftand a bucket wheel secured to the shaft disposed within the casing andspaced from the diaphragm, a packing to reduce leakage along the shaftpast the diaphragm, and means for receiving leakage passing along saidpacking into the space between the diaphragm and the bucket wheel, saidmeans including channels formed in the disk and the partitions and saidchamber.

5. Elastic fluid turbine comprising a casing, a diaphragm having a diskwith a plurality of partitions forming nozzle passages supported on thecasing, a rotor having a shaft and a bucket wheel secured to the shaftdisposed within the casing and arranged to receive fluid from thepassages formed by the diaphragm, the bucket wheel being spaced from thediaphragm, and means including radial bores in the partitions andchannels in the disk for receiving fluid from the space between the diskand the bucket wheel and for removing such fluid from the turbine.

HANS -KRAFT.

